| Fighter | Record | Last Bout |
|---|---|---|
| John Halverson | 16-8-0 (1 NC) | 2008-03-01 |
| John Hathaway | 17-2-0 | 2014-03-01 |
| John Howard | 24-13-0 | 2015-12-10 |
| John Kolosci | 15-9-0 | 2007-12-08 |
| John Lewis | 3-4-3 | 2000-11-17 |
| John Lineker | 31-9-0 | 2019-04-27 |
| John Lober | 5-9-4 | 1998-10-16 |
| John Maguire | 24-9-0 | 2013-06-15 |
| John Makdessi | 18-9-0 | 2023-09-09 |
| John Marsh | 8-7-0 | 2005-04-16 |
| John Matua | 1-4-0 | 1995-07-14 |
| John Moraga | 19-7-0 | 2018-08-25 |
| John Phillips | 22-11-0 (1 NC) | 2020-10-17 |
| John Polakowski | 2-2-0 | 2008-12-13 |
| John Salter | 14-3-0 | 2010-08-28 |
| John Teixeira | 21-2-2 | 2012-06-23 |
| John Yannis | 10-5-0 | 2026-06-06 |
| Johnny Bedford | 21-13-1 (1 NC) | 2014-09-13 |
| Johnny Case | 22-6-0 | 2017-06-25 |
| Johnny Eduardo | 28-13-0 | 2021-10-02 |
| Johnny Munoz | 12-4-0 | 2023-10-07 |
| Johnny Rees | 13-5-0 (1 NC) | 2008-12-10 |
| Johnny Rhodes | 2-1-0 | 1994-03-11 |
| Johnny Walker | 22-10-0 (1 NC) | 2026-10-03 |
| Johny Hendricks | 18-8-0 | 2017-11-04 |
| Jon Delos Reyes | 8-5-0 | 2015-10-24 |
| Jon Fitch | 30-7-1 (1 NC) | 2013-02-02 |
| Jon Hess | 1-1-0 | 1995-04-07 |
| Jon Jones | 28-1-0 (1 NC) | 2024-11-16 |
| Jon Madsen | 8-2-0 | 2011-03-26 |
| Jon Manley | 9-4-0 | 2013-02-23 |
| Jon Olav Einemo | 6-3-0 | 2012-01-28 |
| Jon Tuck | 10-5-0 | 2018-08-25 |
| Jonathan Brookins | 16-10-0 | 2012-12-15 |
| Jonathan Goulet | 23-12-0 (1 NC) | 2010-05-08 |
| Jonathan Martinez | 19-6-0 | 2024-11-16 |
| Jonathan Meunier | 8-1-0 | 2016-11-26 |
| Jonathan Micallef | 10-1-0 | 2026-05-02 |
| Jonathan Pearce | 14-7-0 | 2024-10-12 |
| Jonathan Wiezorek | 11-2-0 | 2004-04-02 |
| Jonathan Wilson | 7-3-0 | 2017-10-21 |
| Jonavin Webb | 9-2-0 (1 NC) | 2016-02-21 |
| Jonny Parsons | 9-3-0 | 2023-07-22 |
| JooSang Yoo | 9-1-0 | 2026-09-19 |
| Jordan Espinosa | 15-9-0 (1 NC) | 2021-03-06 |
| Jordan Griffin | 18-9-0 | 2021-04-10 |
| Jordan Johnson | 10-0-0 | 2018-09-15 |
| Jordan Leavitt | 13-4-0 | 2026-06-06 |
| Jordan Mein | 31-12-0 | 2018-07-28 |
| Jordan Radev | 23-5-0 | 2007-12-29 |